The present invention relates to (a) nitrogen-containing fertilizers, (b) methods for increasing alkaline earth metal uptake by plants, (c) methods for fertilizing plants, and (c) methods for manufacturing nitrogen-containing fertilizers.
Many plants need supplemental calcium for nutrition and disease prevention. However, plants have difficulty absorbing added calcium unless it is combined with one or more nitrogen compounds.
A material currently being used in agricultural practice is a ternary aqueous solution comprising calcium nitrate and ammonium nitrate in a binary eutectic ratio. The ternary solution contains a mole ratio of ammonium nitrate to calcium nitrate of about 1.75. The maximum solution concentration that can be prepared from the ternary solution, while maintaining the crystallization temperature of the solution above or at about -1.1.degree. C. (about 30.degree. F.), is about 30.9 weight percent ammonium nitrate, about 36.2 weight percent calcium nitrate, and about 32.9 weight percent water--for a total nitrogen content of about 17 weight percent. (As used in the specification and claims, the term "crystallization temperature" means the temperature at which crystals begin to form in an aqueous solution as the temperature of the aqueous solution is lowered; and the term "weight percent" means the weight of a particular ingredient present in a solution divided by the total weight of all solubilized solutes and solvents present in the solution, the quotient being multiplied by 100%.)